Announcement PDF ASX:ESR 22 June 2023 Next-Generation Geophysical Program to Commence at Carr Boyd HIGHLIGHTS ➔ Next-generation helicopter-borne TargetEM system to be deployed at Carr Boyd by Expert Geophysics ➔ TargetEM offers significant technology and sensitivity upgrades from previous airborne systems ➔ World-first Audio-Frequency-Magnetic (AFMAG) time-domain data to be collected will vastly improve depth and quality of investigation in potentially detecting drill targets over previous systems ➔ 253km2 survey targets entire Carr Boyd internal and basal contacts along with the nearby Colreavy Komatiite Figure 1: Location of the next-generation TargetEM survey with respect to Estrella’s tenements Estrella Resources Limited (ASX: ESR) (Estrella or the Company) is pleased to announce the signing of an agreement with Canadian-based geophysical firm Expert Geophysics to commence a world-first helicopter-borne electromagnetic survey (TargetEM) at the Company’s Carr Boyd Project, approximately 80km NNW of Kalgoorlie in Western Australia. _________________________________________________________________________________ Office Address London House, Level 8, 216 St Georges Terrace, PERTH WA 6000 Postal Address GPO Box 2517, PERTH WA 6831 Phone +61 8 9481 0389 Fax +61 8 9463 6103 Email info@estrellaresources.com.au ACN 151 155 207 The 253km2 survey will target all of Estrella’s tenure at Carr Boyd as shown in Figure 1, encompassing all prospective horizons identified in the recent exploration review including the high priority Colreavy Komatiite target which has had no previous modern geophysics undertaken. Commenting on the highly anticipated program, Estrella Managing Director Chris Daws said: “I am extremely pleased and excited to be able to inform shareholders that we will be advancing exploration efforts at our 100% owned Carr Boyd Ni/Cu/PGE project. We have always looked to improve our discovery advantage utilising ultra-modern exploration techniques and technology. We were the first to successfully use the revolutionary e-vibe seismic system in W.A. and our team is now employing a world-first in geophysical surveying methods. This is next-gen geophysical system technology that even the majors have not yet utilised. The geophysical survey will cover our entire tenement package at Carr Boyd, some 253km 2, so that we can potentially locate drill targets that have previously evaded detection with older technology. The program will be funded through the recent equity provided by Radium Capital. I look forward to reporting the results as we continue to unlock Carr Boyd’s geological secrets.” The R&D personnel at Expert Geophysics were the developers behind the highly successful and award winning VTEM, ZTEM and Air-MT systems. The TargetEM system contains many structural, electrical, and software improvements over previous helicopter-borne EM systems that have greatly improved the sensitivity and depth of investigation. Estrella will host the first fully commercial deployment of the system at Carr Boyd in July 2023. In addition to airborne time-domain low-noise electromagnetic data, the Company will be acquiring VLF, magnetics and high-frequency AFMAG data. AFMAG acquired on a time-domain system, has never been released commercially. The system and software have been in development and testing for several years; however, Expert Geophysics now wishes to exploit it more widely and is now making it available in Australia. AFMAG technology utilizes naturally occurring electromagnetic fields in the audio-frequency range, which are associated with global lighting discharges. Thunderstorms release energy converted to electromagnetic fields that propagate through the ionosphere-Earth interspace. The electromagnetic fields and currents induced by these fields in the subsurface are used in the combined system to understand differentiation in the electrical resistivity of the subsurface. The advantages of the AFMAG data with respect to Estrella’s Carr Boyd exploration program include: 1. The AFMAG complementary data will allow the system to measure across a broader range of resistivities than any other time-domain system on the market, revealing a more significant distinction of geology and structure at depth. The system can also resolve highly resistive targets. With the seismic data already collected, this will enable true 3-dimensional geological interpretation, which can be used to constrain internal exploration windows and model prospective horizons within the Carr Boyd igneous complex (Figure 1) before drilling. 2. In the case of nickel-copper-PGE type targets, the system can detect "superconducting type massive sulphides”, which are problematic for other time-domain systems, along with significant alteration zones followed by disseminated sulphides. 3. The new system’s capability will also enable recognition of superparamagnetic (SPM) anomalies and compensate for induced polarization (IP) effects which is an issue for other airborne timedomain systems (especially prominent in Australia). These effects create pseudo anomalies and mask the useful inductive EM response. The most intensive IP effects exist in areas of volcanicsedimentary rocks and surficial clay deposits covering parent rocks. This is common across the Goldfields and applies to the Carr Boyd basal contact and the Colreavy Komatiite. 4. AFMAG data measured at the lowest possible frequencies will allow the system to see deeper than any airborne time-domain system. This will be especially useful at Carr Boyd where the basal contacts dip steeply (Figure 2). Figure 2: Depth of investigation of the AFMAG system with respect to traditional airborne EM and the known mineralisation at Carr Boyd The 2023 exploration review collated all previous geophysics survey results gained either on-ground or via aircraft from the 1980’s until present. Anomalies in the data over Carr Boyd exist, however each technique has its limitations and nothing definitive was ever identified or adequately tested, including the T5 discovery made by Estrella. The TargetEM system with the additional AFMAG acquisition gives Estrella the opportunity to update the Carr Boyd conductivity and magnetic models and to incorporate the seismic interpretation along with the recent findings of the collaboration with the CSIRO. The TargetEM system (Figure 3) will be available in July 2023 and Estrella very much looks forward to working with Expert Geophysics in Australia. Figure 3: The TargetEM loop under testing The Board has authorised for this announcement to be released to the ASX. FURTHER INFORMATION CONTACT Christopher J. Daws Managing Director Estrella Resources Limited +61 8 9481 0389 info@estrellaresources.com.au Media: David Tasker Managing Director Chapter One Advisors E: dtasker@chapteroneadvisors.com.au T: +61 433 112 936 Competent Person Statement The information in this announcement relating to Exploration Results is based on information compiled by Steve Warriner, who is the Exploration Manager of Estrella Resources, and a member of The Australasian Institute of Geoscientists. Mr. Warriner has sufficient experience relevant to the style of mineralisation and type of deposit under consideration, and to the activity he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting of Exploration Results, Mineral Resource and Ore Reserves”. Mr Warriner consents to the inclusion in the report of the matters based on their information in the form and context in which it appears. Forward Looking Statements This announcement contains certain forward looking statements which have not been based solely on historical facts but, rather, on ESR’s current expectations about future events and on a number of assumptions which are subject to significant uncertainties and contingencies many of which are outside the control of ESR and its directors, officers and advisers. APPENDIX 1 JORC TABLE 1 – CARR BOYD EXPLORATION Section 1 - Sampling Techniques and Data Criteria Sampling techniques JORC Code explanation • Nature and quality of sampling (e.g. cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. • Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. • Aspects of the determination of mineralisation that are Material to the Public Report. In cases where ‘industry standard’ work has been done this would be relatively simple (e.g. ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (e.g. submarine nodules) may warrant disclosure of detailed information. Drilling techniques • Drill type (e.g. core, reverse circulation, openhole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, facesampling bit or other type, whether core is oriented and if so, by what method, etc). Drill sample recovery • Method of recording and assessing core and chip sample recoveries and results assessed. Measures taken to maximise sample recovery and ensure representative nature of the samples. Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. • Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. The total length and percentage of the relevant intersections logged. • • • Logging • • • Sub-sampling techniques • If core, whether cut or sawn and whether quarter, half or all core taken. • If non-core, whether riffled, tube sampled, Commentary • ESR drilling included diamond core - half core samples with a maximum of 2m and minimum 0.25m length. DD core samples have been half cut with an automatic core saw. • Core is cut and sampled to ensure the sample is representative and no bias is introduced. Cutting of specific, banded or stringer sulphide zoned core is done orthogonal to the banding to ensure there is no bias. • Determination of mineralisation has been based on geological logging, visual sulphide estimates and confirmation using a pXRF machine. Samples were dispatched to an accredited laboratory for multi-element analysis. • Diamond core drilling was used to obtain 6m length samples from the core barrel which are then marked in one metre intervals, based on core block measurements and core recovery. • Samples are selected based on geological logging boundaries or on nominal meter marks. Collected samples weigh a nominal 23 kg (depending on sample length). Samples have been dispatched to an accredited commercial laboratory in Perth for analysis. • Samples are being analysed using a 4-acid digest, ME- ICP for 33 elements and all samples are also being tested for Au & PGE elements using ICP analysis. • Drilling was undertaken using NQ2 sized drill core. • Holes have been collared with mud rotary from surface, HQ rough cored to top of fresh rock then NQ2 cored to EOH. • • • • • • • • Core recovery was recorded by the field crew and verified by the geologist. RQD measurements were digitally recorded to ensure recovery details were captured. Sample recovery in all mineralised zones is high with negligible core loss observed. Diamond core drilling is the highest standard and no relationship has been established between sample recovery and reported grade as the core is in very good condition. Detailed industry standard of collecting core in core trays, marking metre intervals and drawing core orientation lines were undertaken. Core trays were photographed wet and dry prior to sampling. Prior to 2021 drill hole logs were recorded in Excel spread sheets and validated in Micromine Software as the drilling progressed. In 2021 a digital logging system, Logchief, was implemented which validates data as it is recorded and uploads that data remotely to a centralised database. The entire length of all holes are logged. Core is half cut using an automatic core saw to achieve a half-core sample for laboratory submission. The sample preparation _________________________________________________________________________________ Criteria and sample preparation Quality of assay data and laboratory tests Verification of sampling and assaying JORC Code explanation rotary split, etc and whether sampled wet or dry. • For all sample types, the nature, quality and appropriateness of the sample preparation technique. • Quality control procedures adopted for all subsampling stages to maximise representivity of samples. • Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. • Whether sample sizes are appropriate to the grain size of the material being sampled. • The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. • For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. • Nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established. Commentary technique is considered industry best standard practice. • No field duplicates have been collected for DD holes. Field duplicates will be collected once initial results are returned and resampling of the mineralised zones is warranted. • Sample sizes are appropriate to the grain size of the mineralisation. • • • • • Location of data points • • • Data spacing and distribution • • • The verification of significant intersections by either independent or alternative company personnel. The use of twinned holes. Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Discuss any adjustment to assay data. • • • • • • • Prior to 2021 drill hole logs were recorded in Excel spread sheets and validated in Micromine Software as the drilling progressed. In 2021 a digital logging system, Logchief, was implemented which validates data as it is recorded and uploads that data remotely to a centralised database hosted by Maxgeo. Hole CBDD028 is twinning hole CBP042. No other twinning is warranted at this stage. • No adjustments undertaken. Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Specification of the grid system used. Quality and adequacy of topographic control. • Data spacing for reporting of Exploration Results. Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. Whether sample compositing has been applied. • For drill collars, RC and DD holes were surveyed with DGPS equipment using the MGA94, Zone 51 coordinate system. Mineral Resource estimation was carried out on this grid. Topography is relatively flat and control is more than adequate given the early stage of the project. A 3D drone ortho-photographic survey has been used to create a DTM of the project area. Drill data spacing of all drill data is sufficient to establish the degree of geological and grade continuity appropriate for estimating a Mineral Resource. Drill hole spacing ranges from 10m by 10m in the most well-drilled portion of the deposit and broadens to approximately 40m by 80m over the remaining areas. Spacing is adequate to establish the degree of geological and grade continuity for estimating a Mineral Resource. Samples were composited to 1m lengths prior to Mineral Resource estimation. The geometry of drill holes relative to the mineralised zones achieves unbiased sampling of this deposit type. No orientation-based sampling bias has been identified. • • • Orientation of data in relation to geological structure Samples are selected based on geological logging boundaries or on nominal meter marks. Collected samples weigh a nominal 23 kg (depending on sample length). Samples have been dispatched to an accredited commercial laboratory in Perth for analysis. Samples are being analysed at Intertek and ALS Laboratories in Perth using a 4-acid digest, ME- ICP for 33 elements and all samples are also being tested for Au & PGE elements using ICP analysis. For ESR drilling, QAQC included Certified Reference Material (CRM’s) and blank (Blanks) samples inserted at the laboratory. Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the drilling orientation and the orientation of key • • to assay data were Criteria Sample security Audits or reviews JORC Code explanation mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. • The measures taken to ensure sample security. Commentary • • The results of any audits or reviews of sampling techniques and data. • Samples are in the possession of ESR personnel from field collection to laboratory submission in Kalgoorlie. No independent audit or review has been undertaken. Section 2 - Reporting of Exploration Results Criteria Mineral tenement and land tenure status Exploration done by other parties JORC Code explanation • Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. • The security of the tenure held at the time of reporting along with any known impediments to obtaining a license to operate in the area. • Acknowledgment and appraisal of exploration by other parties. Commentary • Carr Boyd Nickel Pty Ltd (a wholly owned subsidiary of ESR) holds a 100% interest in the nickel and base metal rights to the project. • All of the tenements are current and in good standing. • • • • • • • • • • The Carr Boyd Rocks deposit was discovered by Great Boulder Mines, in a joint venture with North Kalgurli Ltd in 1968. The deposit was mined between 1972 and 1975, during which time they explored for additional breccia pipe occurrences near the mine. WMC acquired Great Boulder Mines Ltd in 1975, briefly reopening the mine in 1977 before closing it permanently shortly thereafter due to a collapse in the nickel price. The mine had produced 210,000t at 1.44% Ni and 0.46% Cu before its closure. From 1968 Pacminex Pty Ltd held most of the ground over the CBLC outside of the immediate mine area. Between 1968 and 1971 they conducted extensive exploration programs searching for large basal contact and/or stratabound Ni-Cu deposits. It was during this time that most of the disseminated and cloud sulphide occurrences such as those at Tregurtha, West Tregurtha and Gossan Hill were discovered. Defiance Mining acquired the regional tenements from Pacminex in 1987 and focused on exploration for PGE deposits between 1987 and 1990. In 1990 Defiance purchased the Carr Boyd Rocks mine from WMC and switched focus to the mine area between 1990 and 2001, leaving many PGE targets untested. From 1990 Defiance dewatered the mine to conduct testwork and feasibility studies on the remnant mineralisation. Metallurgical testwork, Mineral Resource estimations, and scoping studies were completed. Around 1996 the focus shifted again to regional exploration for large tonnage basal contact deposits. In 2001 Titan Resources Ltd (Titan) acquired the project and recommenced economic evaluations of the remnant material at Carr Boyd Rocks before embarking on another regional exploration program focusing on the basal contact. An aeromagnetic survey, airborne EM reprocessing, and several programs of RAB and RC drilling were completed. From 2005 Yilgarn Mining entered a JV with Titan and continued with some regional exploration but focused most attention in and around the Carr Boyd Rocks mine. In 2007 Titan was acquired by Consolidated Minerals Ltd (Consmin). Consmin conducted IP surveys and detailed gravity surveys but did not drill any targets before selling the project to Salt Lake Mining (SLM) in 2013. SLM completed limited drilling to meet expenditure commitments, before selling the project to Apollo Phoenix Resources in 2016. Criteria JORC Code explanation Geology • Drill hole information • A summary of all information material to the under-standing of the exploration results including a tabulation of the following information for all Material drill holes: • easting and northing of the drill hole collar • elevation or RL (Reduced Level – elevation above sea level in metres) of the drill hole collar • dip and azimuth of the hole • down hole length and interception depth • hole length • If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. • In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Data aggregation methods Deposit type, geological setting and style of mineralisation. Commentary • Apollo sold the project to ESR in 2018. • The Project lies within the Achaean Yilgarn Craton in a 700km belt of elongate deformed and folded mafic, ultramafic rocks and volcanic sediments intruded by granitoids which is referred to as the Norseman-Wiluna Belt. The belt has been divided into several geological distinct terranes, with the project area lying at the northern end of the Gindalbie terrane (Swager, 1996). The geology of the Carr Boyd area is dominated by the Carr Boyd mafic-ultramafic intrusive complex (“CBIC”). • Several distinctive styles of Ni and Ni-Cu mineralisation have been identified within the CBIC. At the Carr Boyd Rocks Nickel Mine NiCu mineralisation is hosted within several 20 to 60m diameter brecciated pipe-like bodies that appear to be discordant to the magmatic stratigraphy. Mineralisation is hosted by a matrix of sulphides (pyrrhotite, pentlandite, pyrite and chalcopyrite) within brecciated bronzite and altered country rock clasts. • Stratiform Ni-Cu-PGE mineralisation has been identified at several different locations within the layered magmatic complex. • ESR is in the process of re-mapping and reclassifying the Carr Boyd Igneous Complex. Previous “Layered Intrusive” models are misleading as the complex is made up of many overprinted and juxtaposed, smaller layered and non-layered intrusives that have progressed from ultramafic to mafic over time. The complex is better described as a magma feeder zone, where the earliest melts passing through the Morelands Formation have assimilated graphitic sulphidic shales, reached sulphur saturation and deposited nickel sulphides along basal contacts. • These basal contacts are not restricted to the base of the complex, but can form within the complex, wherever access was gained by these earlier flows. • The complex has then been intruded and inflated over time by progressively more mafic, barren magmas to produce what we see today. • Exploration results with all relevant drillhole information are reported in the body of the text. • All drill hole information relevant to this resource report/statement has been included in the appendices. No relevant drill hole information has been excluded. • • Exploration results with all relevant drillhole information are reported in the body of the text. Significant Grade Intersections are reported on a 0.5% Ni cut-off Criteria Relationship between mineralisation widths and intercept lengths Diagrams Balanced Reporting Other substantive exploration data Further work JORC Code explanation • Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. • The assumptions used for any reporting of metal equivalent values should be clearly stated. • These relationships are particularly important in the reporting of Exploration Results. • If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. • If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g. ‘down hole length, true width not known’). Commentary • Composite assay grades are determined by geology and nickel-copper-sulphur content. • Assays are length and SG weighted when calculating average grades over an intersection. • Metal equivalent values have not been used. • Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported. These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. • Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. • Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. • Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. • Relevant diagrams have been included within the Mineral Resource report main body of text. • All new drillhole information within this announcement is reported • • • • No other substantive data exists. Everything meaningful and material is disclosed in the body of the report. Geological observations are included in the report. No bulk samples, metallurgical, bulk density, groundwater, geotechnical and/or rock characteristics test were carried out. There are no known potential deleterious or contaminating substances. Further work by ESR may include a Scoping Study for the T5 Mineral Resource estimate. Refer to diagrams in the body of text within the Mineral Resource report. Diamond drilling and DHTEM geophysical testing is continuing. • The nature and scale of planned further work (e.g. tests for lateral extensions or depth extensions or large- scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. • • • • • • • Most drill holes were angled to 060° or 270° so that intersections were orthogonal to the orientation of mineralisation. True widths have been stated where possible however, the variable orientation of mineralisation within magma feeders combined with a structural overprint and steep drill angles make true width calculations highly misleading. Section 3 Estimation and Reporting of Mineral Resources Criteria Database integrity JORC Code explanation • Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. • Data validation procedures used. Site visits • • Geological interpretation • • • • • Comment on any site visits undertaken by the Competent Person and the outcome of those visits. If no site visits have been undertaken indicate why this is the case. Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. Nature of the data used and of any assumptions made. The effect, if any, of alternative interpretations on Mineral Resource estimation. The use of geology in guiding and controlling Mineral Resource estimation. The factors affecting continuity both of grade and geology. Commentary • The data for this Mineral Resource estimate was collected and logged using Excel spreadsheets and validated using Micromine Software. The data will be loaded into an externally hosted and managed database. • It is assumed that due care was taken historically with the process of transcribing data from field notes into digital format for statutory annual reporting. • All assays were reported by laboratories in digital format reducing the likelihood of transcription errors. • No site visit has been conducted by the Competent Person, due to the level of study so far conducted at the Project.